203* Thermostat and Billet Housing

[DocB]

I plan on replacing the OEM with the above and would like to know how much fluid loss you experienced when you did yours.
Would like to have the makeup fluid on hand.
Any TIPS when installing?
BTW, did you notice a difference afterwards?

[keystone crawler]

i don't know of that many people that change just a t-stat without chaning and flushing the coolant. i've seen guys us a large hose pliers and do that man does that make a mesh like can't believe

[fleastang]

It is a simple job. That would be the time to flush and fill with fresh coolant and coolant additive. I just flushed mine and changed the thermostat, hoses, and used new stainless hose clamps. You can drain the coolant using the radiator pet**** on the drivers side. If you flush you can also drain the block by removing plugs in the block the easiest being the drivers side at the back. It is basically a pipe plug and a 1/4" ratchet head will work perfect. You also would benefit when adding water back in to use distilled water ($1.00 a gallon at the grocery store). Total job will use about 6 gallons (antifreeze/water mix) with 7 at best.

[DocB]

Thanks, good advice to flush when installing new tstat,
BUT I just put in a new water pump and fluid.
Wish I would have known about the 203* before.
I can just drain and refill the fluid, right?
Did you put RTV under the housing? And what kind?
About hoses, how long before you change them?

[keystone crawler]

if have a clean dain pan like spotless you can reuse it . i like to use the paper gasket normal in the packet most of the newer cars are going to o -rings to seal them

[fleastang]

You can drain and refill but while you are at it with the thermostat out it is good to go ahead and flush out all the old stuff with the drain plugs out. I did not use any chemicals to clean mine; I had maintained it well and did not have any build-up to speak of so I just flushed it well with water until it ran clear and that was with the hoses off and thermostat out. Before you put the new thermostat in fill up the engine at the thermostat hole with your 50/50 mixture and top it off then install the thermostat. The thermostat housing uses an o-ring so put in a new one when you change the thermostat. No RTV required! The thermostat goes in first and the o-ring on top; it will fit in the recess. Good luck.........

[DocB]

Thanks men for the advice.
Question?
A gasket came with the new tstat, but it is square and not round(cross-section). It goes on top of the new tstat, is there another oring that goes under the new housing?
This is my first time, so please be gentile!

[fleastang]

Sorry for the late reply but what you have is correct. The rubber o-ring cross section is indeed square; guess we can call it a square ring instead or would that be a square o-ring or one of those "you know what I mean" parts. And it does go on top and nothing else except to bolt down the housing with the 3 factory bolts.(some people replace the housing because they tend to rust/corrode slightly on the face where it meets the gasket.)